A system for the objective analysis of physiological data (EEG, EMG, EOG, NPT, periodic leg movements, respiration, oxygen saturation level, and body temperature) occurring during sleep, is to be designed and evaluated. The system will include a token generator (signal processor) interfaced to a host computer. The token generator will detect and quantify the waveforms of interest and transmit the information to the host computer. The host (a personal computer based system) will be designed using an expert system design shell and will include a knowledge base, knowledge base editor, user interface, interactive graphics and a data base management system. The result will be a system easy to use by operators not familiar with computers or signal processing and one which can readily be expanded as more knowledge about the system and sleep analysis are acquired. The research will include systematic studies, by two independent sleep laboratories, to demonstrate the utility and validity of the information obtained from automated analysis. These studies will also provide information which will be used to further improve the system design. The resulting system will provide a much more detailed description of the sleep process than is now possible, increase standardization of sleep studies, and provide a means for bringing sleep studies to a larger patient population.